Transfer copying materials



May 2, 1944. J. GROAK TRANSFER COPYING MATERIALS Filed- June 10, 1942 used to mask the colouring matter.

Patcnte'dMay 2, 1944` rUNITEDI. tiran-.s PATENT n g '2,343,128 TRANSFER. dorme. Mamma Josef Groak, Hendon, England Application :une io, mz, ser-m No. 446,536

A 1n om: mam im so. 1941 1s claims. (cl. zsz-zs) This invention relates to transfer copying mato anadjacent `sheet or on separate interleavedv sheets.

It is an object of the present invention to provide transfer copying materials, which operate without the transference of colouring matter, and in such manner that the colouring matter of which the copied writing is composed is not visible on the unused materials and only becomes visi' ble after copying where the writing impressionv Occurs.

According to the invention, a set of transferv copying materials comprises one or more copy sheets ycarrying a dyestui! or like colouring matcase the colouring matter will be masked to a considerableextent by the cellulosic fibres if no masking pigment is used.

As the substance which brings the colouring matter into the dissolved condition there is used a solvent for the c olouring matter, if desired in 'ter in an undissolved and dispersed conditiomand y one or more transfer sheets carrying a transfer coating comprising a transferable material capable, when transferred tothe copy sheet under the writing impression, of bringing the coloring mat terinto a dissolved condition exhibiting a coloration which contrasts with the surface of the copy sheet carrying the undissolved and dispersed coloring matter.

' The colouring matter. for example a fat or alcohol soluble dyestuff or dye base, such as a Typogen dyestuff. may be applied to the copy sheet` inundissolvedand dispersed condition in any desired manner. and it will be understood thatv thequantity so applied will not be sufilcient to impart any strong coloration to the sheet so that an adequate ,colour contrast is produced by the action of the vsubstance which brings the colouring matter into the dissolved condition. It may: however, be deplying the colouring matter to a whitepaper sheet a white pigment, such as titanium white, may be Instead of mixing the masking pigment with the colouring matter it may be applied as a separate layer over the colouring matter. The dispersed colouring matter may also be incorporated in the paper pulp during the manufacture of the sheet, and in this conjunction with an agent which assists the dissolution of the colouring matteror converts the latter into a soluble form. 'There may be used,

for example, a dyestu which isY soluble in an organic medium. such as a fatty, oily or waxy sub-- stance. used. as the solvent in the transfer coating. For this purpose'the so-called fat or oil soluble dyestuii's are suitable, in conjunction with organic media in which they are soluble, forf example, relatively. non-volatile alcohols or'r ethersthereof,

waxes, fatty acids, esters of phthalic'acid, phos` phoric acidor other organic or inorganic acids,

and-other relatively non-volatiiejorganic solvents.

Among the alcohols there may be mentioned fatty alcohols. for example, cetyl alcohol-'or oleyl alcohol .(Ocenol") or mixtures of fatty alcohols, such as Lanette wax; polyhydric alcohols, for example, ethylene glycol; and benzyl alcohol. Suit-` able fatty acids are, for example, oleic acid, ri'- cinoleic acid, nut oil. fatty acid. palm nut oil fatty acid, stearic acid, palmitic acid, montanicjacid, lauric acid and capric acid'. `,As esters of organic or inorganic acids there may be mentioned butyl laurate, ethyl oleate, butyl ricinoleate, butyl stea- "rate, diamyl tartrate, dibutyl tartrate, methyl gly-f col phthalate, benzyl butyl phthalate, dibutyl phthalate, sextol phthalate, triphenyl phosphate, 'tricresyl phosphate and triacctin. It has been found that organic acids, for example, fatty acids, resinic acids or aromatic acids, such as benzoic acid or toluic acid, assist the dissolution of the dyestuis, more' especially basic dyestufs. functions of solvent and solution assistant may be combined in a single substance, and for this purpose oleic acidfor ricinoleic acid may be used. Furthermore, a wax or waxy substance used in making the transfer coating may act as4 the lsolvent, and waxes containing free organic acids, for example, montan wax, are especially suitable as they combine the functions of solvent and solution assistant. It is, however, generally preferable to employ a solvent of higher solvent power in addition to the wax, especially when such a solvent has a plasticising action on a wax which might otherwise be too hard to eil'ect a satisfactory transfer. -In the case of solvents, such as ethylene glycol, which are not miscible with waxes they may be emulsiied with the wax, and then,

The

. if necessary, a plasticiser may be added to soften the wax.

The inventionv is not confined to the use of an organic solvent medium, and is also applicable toV aqueous media as' solvents. For this purpose a water-soluble dyestuif may-be applied to the copy sheet in an-undissolved and dispersed condition, and the transfer coating may contain an aqueous medium emulsiiled or dissolved therein. As an aqueous medium a hygroscopic substance, such as glycerin, containing water may be used,

which medium is emulsiiied or dissolved in the water-insoluble dyestuff, in which case the transfer coating will contain in addition to the aqueous medium a wetting agent, such as a sulphonated fatty acid or alcohol or a wax soap, which assists the dissolution of the dysstuif or converts it into a water-soluble form. For this purpose sulpho-ricinoleic acid may be used in commotion with S.- R. A.- dyestus.

The known waxy or other transfer composi tions used for preparing carbon or like transfer materials, but without the dyestuif or pigment, are suitable for application to the transfer sheet used lin this invention, provided that such compositions have adequate solvent properties with respectto the colouring matter used in the copy sheet, or provided that suitable solvents or solution assistants are incorporated therewith. 'I'he composition may be applied hot or cold in known manner uniformly or in patches to the surface of the transfer sheet. If the oily or fatty substances customarily used in transfer compositions for softening or plasticising the wax have fugitive printing inks and consistii'gf'of a glycerine solution of dextrin or gum in the psual proportions, or a vehicle consisting ofA a mixture of paraffin oil and ester gum. Thedispersion prepared with either. of these vehicles may contain about 3-6 per cent of an appropriate dyestuff and about 10-15 per cent of a masking pigment, for example, titanium white.

Various forms of copying materials made in accordance with the invention are shown by way of example inthe accompanying drawing in which:

Figure l shows in cross section on an enlarged scale a pair of transfer' and copy sheets,

Figs. 2 and 3 show inplan and cross section,

respectively, a'special form of copy sheet,l

Figs. 4 and 5 show in plan view a set of childrens tracing papers.

Fig. 6 shows in cross section a copy sheet having a transfer coating on its lower surface,

Fig. 7 shows in cross section a set of two kinds of copy sheets having transfer coatings on their lower surfaces, and

Fig. 8 shows in cross section a pair of transfer and copy sheets provided with protective films.

The transfer sheets may be prepared as original sheets I on which the writing is to be performed', and with the transfer coating 2 applied to the back uniformly orin patches at selected places, as in the case of the known'back carbonised'stationary. Alternatively, the transfer sheets may be made of suitably thin material for use as separate interleaved transfer sheets.

A single colouring matter 4 or mixture of colouring matters giving an appropriate mixed colour may be applied uniformly or in patches to the copy sheet 3. Colouring matters, or mixtures of colouring matters, giving different colours may be applied to different areas of the insufficient solvent action, there may be used ment or starch, in the transfer composition to Y reduce the tendency of the solvent to bleed on the copy sheet, and so to obtain greater sharpness in the copy. Other ingredients may be incorporated in the transfer composition, for example, a xative for basic dyestuis, such as calcium stearate, and agents to counteract rancidity, -such as phenol or para-hydroxy-benzoic acid.

The colouring matter may be coated on the copy sheet by applying thereto a dispersion of the colouring matter in a non-'solvent liquid medium, advantageously an aqueous medium, containing a binding agent. Suitableebinding agents are casein, dewaxed shellac (which in either case may be vdissolved in a weal; aqueous solution of'borax), or dextrin. It is also of advantage to add a binding when the dispersed colouring matter is incorporated in the paper pulp. vas this leads toa better xation of the colouring matter;

The dispersion of the undissolved colouring matter may be applied locallyl in the form of a coating by a printing process. In this cas 'les copy sheets, where it is desired that separate data should be recorded in distinct colours. It is also possible as shown in Figs. 2 and 3 to overprint areas 5 producing one colour on the copy sheet 3 locally, for example in patches or lines, with a composition producing a different colour. 'I'his may be done when the copy sheets take the form of cheques on which the copied writing will appear in two colors. U As shown in Figs. 4 and 5, childrens tracing-papers may be made by printing drawingsfor example, a flag as shown in Fig. 4, on the upper surface of the transfer sheets I, and applying appropriate colour producing compositions to the areas a, b and c of the copy sheet which lie beneath the parts A, B and C of the drawing which are to be reproduced in different colours.

When it is desired to produce several copies simultaneously the copy sheets 3 may have the transfer coating 2 applied to their lower surfaces as shown in Fig. 6. In order to reduce the risk of the'solvent in the transfer coating penetrating through the paper and acting on the colouring matter on the upper surface, it is advisable to apply a layer of, or impregnate the paper with, a suitable solvent repelling substance before applying the transfer coating or the colouring matter. Casein is a suitable substance for repelling a fatty or oily solvent. Such a layer may be applied at 8 or 9 or at both 8 and 9 as shown in Fig. 6. The risk of solvent penetration may also be circumvented as shown in Fig. 7 by applvlng to the upper surface of the copy sheet 3' a colouring matter l' which is insoluble in the solvent used in the transfer coating '2 on the lower surface. The upper surface a,s4s,1as v as fouows: 0.5 pm of borsxyis dissolved in so.

of the next lower copy sheet 3" will then contain a colouring matter 4" soluble in the solvent contained in the superposed transfer coating 2", i

[but insoluble in the solvent contained in the transfer coating -2' on its lower surface. Thus,

' two kinds of copy "sheets 3, 'and'f will be rehydric alcohol as solvent, and on the other kind carrying on its upper surface a dyestuf! which is soluble in polyhydric alcohols but not fat-soluble and on its lower surface a transfer coating containing a fatty solvent. For this purpose there is advantageously used as solvent ethylene glycol emulsifled in a waxy transfer medium, and Nigrosine (alcohol soluble) may be used as the polyhydric alcohol-soluble dyestuif. These two kinds of sheets are arranged-in alternation with their transfer coatings downward as shown in Fig. 7.

In order to reduce the risk of premature interaction between the transfer surfaces and the colour producing surfaces ydue to rubbing or slight pressure when the sheets are in contact, there may be applied, as shown in Fig. 8, over parts of water, and 3 parts of casein fare-dissolved in the Vbor'ax solution. The resulting solution is ground with 3 parts ofrNubian Black,2 I

parts of titanium parts of IndulinezBase A and l() white.

XExample 2 The copy sheetis the same as that described in Example l, and the transfer sheet is prepared as follows: 30 parts of bleachedl montanvwax, 2l parts of tricresyl phosphate and 6 parts of benzoic acid are thoroughly mixed together while heating as described in Examplel. v

The resulting composition is applied to the paper as described in that example.

Example 3 is" dissolved in 60 parts of water. and 3 parts of the transfer coating 2 and/or over the color s producing surface 4 a thin protective film I0, for example of paraffin wax or casein, in the form of a continuous coating or a coating of fine particles which can be penetrated during copying. The penetrable protective film |0 is one which, under the pressureof the writing instrument, can be broken through as in the case of a continuous coating of parafn wax, or can be permeated as in the case of a coating of particles of wax or casein or of a continuous coating of casein.

The transfer coating may also have incorporated therewith substances whlch'are transferred together with the solventl and serve prevent or detect forgery in the copy as described in British Patent No. 503,695, dated February 3, 1938.

The .following examples illustrate the invention, the parts being by weight:

Example 1 The coating composition for the copy sheet is prepared as follows:

8 parts of casein are stirred with 100 parts of water containing 8 parts of a concentrated solution of ammonia until the casein is dissolved, and then the ammonia is allowed to evaporate. To the casein solution are added 60 parts of titanium white, 4 parts of Induline Blue base and 10 parts of Nubian Black (marketed by Messrs. Williams (Hounslow) Ltd.). until the colour of the dyestufis has disappeared. The resulting suspension is applied to the paper, while keeping the suspension well agitated.

The transfer sheet is prepared as follows:

28 parts of prime yellow carnauba wax, 'l parts of Lanette wax (a mixture of cetyl and octadecyl alcohols) and 17 parts of methyl glycol phthalate are melted together over steam and thoroughly mixed. The resulting transfer composition may beapplied as a uniform coating or printed locally on the paper while hot, the paper being chilled immediately after the application of the coating inthe manner known when applying waxy transfer compositions.

instead of the coating composition described above, there may be used a composition prepared The whole is stirred I casein are dissolved in the borax solution. l0 parts of Methyl Violet Base 10B are mixed with 30 parts of molten ester gum, and the solidified mixture is pulverized. 6 parts of the powdered mixture and l5 parts of titanium white are ground with the casein-borax solution described above.

The copy sheet coatedwith the above composition gives a bluish. violet colora-tion with any of the tmnsfer compositions of Examples 1 and 2, 9-11 and 13. Y

'Ihe following are examples in which the'colouring matter is incorporated in the pulp `used for making the copy sheet:

-- Example 4 2.5 parts of Nubian Black are ground with 10 parts of titanium dioxide in water. The resulting mixture is incorporated in a beater with parts of sulphite cellulose pulp, to which size and alum have previously been added. The paper prepared with this pulp gives a blue-black co1- oration when used in conjunction with any of the transfer compositions described in Examples 9-13.

Example 5 Example 6 2 parts of Oil Brown (dye powder) and 3 parts ofv the powdered mixture. of Methyl Violet Base 10B and ester described in Example 5 are ground with 5 parts yoftitanium dioxide andy 5 parts of clay. 'I'he resulting mixture is incorporated with 100 parts of pulp as described in Example 4. The paper obtained therewith gives a brown coloration with any-of the transfer comi positions of Examples 9-13.

.Example 7 v 40 parts of Induline Base A are mixed with-25 parts of molten ester'gum, and the solidified mixture is pulverised. 6 parts of the powdered mixture are ground in water with 10 parts of titanium while. Theresulting mixture is incorpo-.-`

rated with 100 parts U11-pulp a8 described in EX- ample 4. The paper obtained therewith gives a.

blue coloration with any of the transfer compositions of Examples 9*-11 and 13.

sample s and 5.parts'of clay. The resulting mixture is incorporated with 100 parts of pulp as described in Example 4. The paper obtained therewith gives a green` coloration with the transfer composition' of Example 12.

In order to improve the fixation of the dyestuif y in A'the pulp the mixture of dyestuif and pigment,

instead of being ground in water, may in each of Examples 4-8 be ground .in a solution of 6 parts of casein and l part of borax in 50 parts of water.

The following are examples of suitable transfer compositions. In each case the ingredients are mixed together by melting over steam; and the composition is applied to the paper in the manner described in Example l.

Example 9 Parts Prime .yellow carnauba wax 80 Brofo wax Y/554 (a hard wax marked by Messrs. Brown and Forth Ltd., as a substi- I'he composition of this example is suitable for use only in conjunction' with fat-soluble dyestuffs, and not -dyestui bases.

Iclaim: y'

1. A set of transfer Acopying materials comprising at least one copy sheet carrying a, color. ing lmatter in an undissolved and dispersed condition, and atleast one transfer sheet carrying a transfer coating comprising a transferable material capable, when ltransferred to the copy sheet under the writingiinpression, of bringing the coloring matter into agidissolved condition exhibiting a coloration which contrasts with the surface of the copy sheet .carrying the undissolved ancldispersed coloring matter. Y

2. A set' o f transfer copying materials as claimed in claim l, wherein the transferable material comprises a solvent for the coloring matter carried by the copy sheet. l

3. A set of transfer copying materials as claimed in claim l, wherein the transferable material comprises a solvent and a solution assistant for the coloring matter carried by the copy sheet.

4. A set of transfer copying materials comprising at least one copy sheet carrying a coloring matter in an undissolved and dispersed condition and a pigment which at least partially masks the color of the dispersed coloring matter, and at least one transfer sheet carrying a transfer coating comprising a transferable material capable, when transferred to the copy sheet under the writing impression, of bringing the coloring matter into a dissolved condition exhibiting a coloration Awhich contrasts with the surface of the copy sheet carrying the undissolved and dispersed coloring matter.

. 5. A set of transfer copying materials as claimed in claim 4, wherein the transferable material comprises a solvent for the coloring matter carried by the copy sheet.

6. A set of transfer copying materials comprising at least one copy sheet having a coloring matter dispersed in undissolved condition within the pulp. 0f which the sheet is composed, and at least one transfer sheet carrying a transfer coating comprising a transferable material capable, when transferred to the copy sheet under the writing impression, of bringing the coloring matter into a dissolved condition exhibiting a tute for montan wax) 50 Russian tallow 30 Butyl stearate 45v Pale olein (oleic acid) 10 Brown SO olein (oleic acid). -5 Tricresyl phosphate 20 Ocenol (oleyl alcohol) 15 Petroleum jelly 5y Phenol v 1 Calcium stearate 5 Para-hydroxy-benzoic acid 1 Example 1,0 Parts Prime Yellow carnauba wax f, l `30 lrofo wax Y/554 30 Distilled white nut oil fatty acid 30 Butyl stearate 15 Butyl ricinoleate v15 Example 11 Y Y Parts Carnauba wax 30 Brofo wax Y/554 20 Beeswax 10 Distilled white nut oil fatty acid 70 Example 12 1 Parts Prime Yellow carnauba wax 30 Cetyl alcohol 60 Butyl ricinoleate 30 Butyl ricinoleate 2o 'is coloration which contrasts with the surface of the copy sheet carrying the undissolved and dispersed coloring matter.

7. A set of transfer copying materials comprising at least one copy sheet having incorporated within the pulp of which the sheet is composed a coloring matter in undissolved and wpersed condition and a pigment which at least partially masks the'color of the dispersed coloring matter, and at least one transfer sheet carrying a transfer coating comprising a transferable material capable, when transferred to the copy sheet under the writing impression, of bringing the coloring matter into a dissolved condition exhibiting a coloration which contrasts with the surface of the copy sheet carrying the undissolved and dispersed coloring matter.

8. 'A set of transfer copying materials comprising at least one copy sheet carrying a coating of a coloring matter in undissolved and dispersed condition and a binding-agent for the coloring matter. and at least one transfer sheet carrying a transfer coating comprising a transferable material capable, when transferred to the copy sheet under the writing impression, o1' bringing l the coloring matter into a dissolved condition exhibiting a. coloration which contrasts with the surface of the'copy sheet carrying the undissolved and dispersed coloring matter.

9. A set of transfer copying materials compris. ing at least. one copy sheet carrying a coloring matter in an undissolved and dispersed condition, and at least one transfer sheet carrying a coating of a waxy transferable materialcomprising a solvent capable, when transferred to the copy sheet under the writing impression, of bringing the coloring matter into a dissolved condition exhibiting a coloration which contrasts with the surface of the copy sheet carrying the undissolved and dispersed coloring matter.

10. A set of transfer copying` materials as claimed in claim. 9, wherein the waxy transferable material comprises, in addition to the solvent, a solution assistant for the coloring matter carried by the copy sheet.

11..A set or transfer copying materials comprising at least one copy sheet carrying a color- .ing matter in an undissolved and dispersed condition, and at least one transfer sheet carrying a coating of a transferable material comprising a relatively non-volatile solvent consisting of an alcohol, which solvent is capable when transferred to the copy sheet under the writing iinpression, of bringing the coloring matter into a dissolved condition exhibiting a coloration which contrasts with the surface of the copy sheet carrying the undissolved and dispersed coloring matter.

12. A set of transfer copying` materials com-'- prising at least one copy sheet carrying a coloring matter in an undissolved and dispersed condition and-a thin protective film over the co1- oring matter which canv be penetrated during copying, and at least one transfer sheet carrying a transfer coating comprising a transferable material capable, when transferred tc the copy sheet under the writing impression, of `bringing the coloring matter into a dissolved condition exhibiting a coloration which contrasts with the sur-- face of the copy sheet'carrying the undissolved and dispersed coloring matter.

13. A set of -transfer copying materials prising at least one copy sheet carrying a coloring matter in an undissolved and dispersed condition, and lat least one transfer sheet carrying a transfer coating comprising a transferable material capable, whenl transferred so the copy sheet under the writing impression, f bringing the coloring matter into a `dissolved condition exhibiting a. coloration which contrasts with the surface of the copy sheet carrying the .undis- 1 solved and dispersed coloring matter, the said com.-

.dissolved and dispersed condition, and on the other surface thereof a transfer coating comprising a ,transferable material capable, when transferred to the surface of another of the sheets carrying the said coloring matter, of bringing the coloring matter into a dissolved condition exhibiting a coloration which contrasts with the surface of the-sheet carrying the undissolved and dispersed coloring matter.

16. A set of transfer copying materials comprising a plurality of sheets each carrying on .one surface thereof a coloring matter in an undissolvedand dispersed condition, and on the other surface thereof a transfer coating comprising a solvent capable, when transferred 'to the copy sheet under, the writing impression, of bringing the coloring matter into a dissolved condition exhibiting a coloration which contrasts with the surface of the copy sheet carrying the undissolved and dispersed coloring matter, and each of the said sheets having interposed between the coloring matter and the transfer coating a material which prevents the solvent from coming into contact with` the coloring matter.

17. A set of transfer copying materials comprising at least one sheet carrying on one surface thereof a coloring matter inv an undissolved and dispersed condition and on the other surface thereof a transfer coating comprising a solvent incapable of dissolving the said-coloring matter, and at least one other sheet carrying on one surface thereof in an undissolved and dispersed condition a coloring matter soluble in the solvent carried by the rst mentioned sheet and carrying on the' other surface thereof a transfer coating comprising a solvent incapable of dissolving the coloring matter on the opposite surface but capable ofl dissolving the coloring matter carried bythe first mentioned sheet, each of which solvents is capable, when transferred to the surface of a sheet carrying coloring matter solubletherein, of bringing the coloring matter into a dissolved condition exhibiting a coloratransfer coating having thereon a thin protective film which can be penetrated during copying.

14. A set of transfer copying materials comprising at least one copy sheet carrying a basic dyestuif in undissolved and dispersed condition. and at least one transfer sheet carrying a transferable material 'comprising al solvent for the basic dyestuifand an organic acid which assists the dissolution of the basic dyestud, which 'scl' vent and acid, arecapable, when transferred to .the copy sheet under the writing impression, of

bringing the basic dyestuil into a dissolved condition exhibiting a coloration' which contrasts with the surface of the copy sheet carrying the undissolved and dispersed basic dyestuif.

15. A set of transfer copying materials cbm' prlsing a plurality of sheets each carrying on one surface thereof a coloring matter in an untionV which contrasts with 'the surface of the sheet carryingv the undissolved and dispersed dyestufl'.V

. 18. A set of transfer copying materials 'com-1 prising at least one copy sheet carrying a color ing'matter in an undissolved and dispersed con` dition, and at least one transfer sheet carrying a coating of a transferable material comprising a relatively non-volatile solvent consisting of a wax, whichsolvent is capable when transferred to the copy sheet under the writing impression, of bringing the coloring matter into a dissolved condition exhibiting a coloration, which contrasts with the. surface of the copy sheetcarrying the undissolved and dispersed coloring matter.-

19. A set of ,transfer copying materials. coniprising .at least one copy sheet carrying a coloring matter in an undissolved and dispersed condition, and' at least one transfer sheet carrying a coating of .a transferable material comprising sheet carrying the undissolved and dispersed coloring matter.

cosas' encara 

